Warning: If you're reading this page, you're already experiencing the symptoms. It's too late.
Causes:
I stayed up too late playing VR.
I played too many hours of space-simulator.
Consult an expert (just kidding, there are no experts in this field).
Remedies:
Try gravitational socks. They're a thing.
Just lie down and whimper until it passes.
Disclaimer: The information provided here is completely fabricated and not actually helpful.
Side effects of zero-gravity sickness may include: unrelenting giddiness, uncontrollable giggling, spontaneous space-dancing, and/or spontaneous combustion.